Oxidation Kinetics of Some Nickel-Based Superalloy Foils in Humidified Hydrogen and Electronic Resistance of the Oxide Scale Formed Part II
| Autor: | Anil V. Virkar, Diane M. England |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Materials science
Hydrogen Renewable Energy Sustainability and the Environment Anodizing Metallurgy Oxide chemistry.chemical_element Condensed Matter Physics Inconel 625 Chromia Surfaces Coatings and Films Electronic Optical and Magnetic Materials Corrosion Superalloy chemistry.chemical_compound chemistry Chemical engineering Materials Chemistry Electrochemistry Inconel |
| Zdroj: | Journal of The Electrochemical Society. 148:A330 |
| ISSN: | 0013-4651 |
| DOI: | 10.1149/1.1354611 |
| Popis: | Foil specimens of Haynes 230, Hastelloy X, Inconel 718, and Inconel 625 of 4.5 mil (∼113 μm) thickness were oxidized in wet hydrogen for several hundred hours at temperatures between 700 and 1100°C. Chromia was determined to be the predominant oxide phase in the scales of these alloys, consistent with the results of a previous study 1 of these alloys in air, as shown using X-ray diffraction and electron probe microanalysis. The oxidation kinetics of all the alloys, investigated by thermogravimetry, in a wet hydrogen atmosphere exhibited parabolic behavior. Haynes 230 and Hastelloy X exhibited the slowest oxidation kinetics of all the alloys studied. Further, the oxidation kinetics of all the alloys were faster at 800°C in a wet hydrogen atmosphere compared to oxidation in air at 800°C. However, the oxidation kinetics of these alloys in a wet hydrogen atmosphere were slower than those in air at 1100°C. The oxide scale formed in wet hydrogen exhibited a higher resistance than that formed in air. This result is attributed to the expected p-type conductivity of the oxide scales formed in both air and wet hydrogen. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|